Air operated double diaphragm pumps have been known and used for many years for a variety of applications. In recent years plastic molded versions of such pumps have become increasingly popular due to the increased chemical compatibility offered by the various plastic materials available. Such plastic pumps have been mainly popular in the smaller sizes as larger size plastic pumps typically have been required to be manufactured out of a metal in order to achieve sufficient strength for those larger sizes.
While various rib designs have been utilized to increase the strength of the fluid housings, such housings still tended to have relatively low burst strengths or require the use of stronger filled materials in order to achieve sufficient strength.